Improvement in let-off mechanism for looms



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Letters Patent No. 90,996, dated June 8, 1869.

IMPROVEMENT IN LET-OFF MECHANISM FOR LOOMS.

The Schedule referred :to in these Letters Patent and making part of the same.

To all whom it ana/y concern Be it known that I, WILLIAM R. CLARK, of North Adams, in the county of Berkshire, and State of Massachusetts, have invented a new and improved LetvOfi Mechanism; and I do hereby declare that the following is a full, clear, and exact description thereof', which will enable others skilled in the art to make and use the same, reference being had to the, accompanying drawings, forming part 0f this specifipationl This invention relates to improvemeiits in leto` apparatus for looms, designed to provide a simple and eiicient means for regulating the tension of the yarn, capable of ready adjustment for yarnsvarying in size.

The invention consists in an arrangement of wormgcaring and bell-crank levers, for varying the pressure of friction-str2 ps on the beamlheads, as hereinafter more fully specified. 1

Figure l represents an elevation of a lom-frame, showing the yarn-beam, and

Figure 2 represents atransverse sectional elevation of the same, taken on the line x x.

Similar letters of reference indicate corresponding partsl I A represents bell-cranks pivoted to the'lom-fra'me at B, and provided with adjustable slides C, upon their horizontal arms, bearing upon the upper edges of the friction-strap levers, D.

The other arms of these bell-cranks ferm toothed segments capable of gearing with the wormrears E,

`upon the shaft F, pitched in opposite directions.

The shaft F derives motion, through other wormgears, C, from a shaft, H, driven from the yarn-beam by bevel-gears.

As the yarn is drawn from the beam, and the diameter of the roll gradually reduced, 'the motion imparted by the gearing'to the segmental bell-cranks will grad.- ually raise the horizontal arms thereof,l reducing the pressure on the levers D, and thereby the friction on the drums of the beams.

The slides C are made adjustable on the bell-cranks, to or from the centre of motion thereof, to graduate the friction to yarns of different sizes, or numbers, and the horizontal parts of the said bell-cranks may be marked with numbers indicating the predetermined position of the slides for yarn of corresponding nnmbers.

For the larger sizes of. yarns, the slides should be nearer theouter ends of the said horizontal parts of the bell-cranks.

One or more bell-cranks and friction-straps may be employed, as preferred.,

Having thus described my invention,

I` claim as new, and desire to secure by Letters Patent- The combination, with the levers D and friction straps, of the bell-cranks having adjustable slides, and

operated substantially as specified.

W. R. CLARK.

Witnesses GEORGE FRENCH, GEO. BPERRY. 

